The existence of electromagnetic fields around a conductor is well known. Early work in studying the relationship between an electric current and a magnetic field established that a compass needle was deflected when placed near a conductor carrying an electric current. Through various experiments, AndreMarie Ampere determined the shape of the magnetic field about a conductor carrying current.
The interaction between magnetic fields and conductors forms the basis for the generation of electricity today. Large power generators produce electricity by conductive wires being rotated within magnetic fields. Motors, solenoids, transformers, and many other electric devices rely on the relationship between conductors and magnetic fields to operate. A galvanometer is a sensitive instrument for detecting feeble currents which relies on the interaction between two magnetic fields, one induced by an electric field and the other emanating from a permanent magnetic.
Yet the problem remains as to how to teach this interaction to students as they begin to explore the world of physics. Seeing an electric motor spin does not teach the student about the shape of, and interaction between, electromagnetic fields. Few students have the skills or equipment to build their own testing devices, such as solenoids, miniature electric motors, galvanometers or the like. If the student is not mechanically skilled in building an experimental device, it may not operate properly and thus will fail to teach the desired lesson. In a classroom, the student may not understand the interaction of forces because he does not receive any hands on experience. Often the student and teacher alike are helped by conducting experiments with simple tools to begin their study toward understanding the interaction of various forces in nature. Simple tools are needed that will aid a person in the study of electric current, electric and magnetic fields, the interaction of electromagnetic fields, and various forces as they exist in nature or as made by man.